(May 10, 2010) For decades, we have known that heavy metals and chemicals can cause grave physical harm. Going back to Rachel Carson's "Silent Spring," we have known and been amply warned of the serious consequences of using or being exposed to these poisons in our daily activities. Thousands of these are well-documented carcinogens.

Building on Carson's ground-breaking research, we also know that certain kinds of chemicals can and do disrupt human [and other animals'] entire immune system.

Going back 30 years, researchers were investigating what became known as endocrine [hormone] disrupting chemicals and how they were affecting frogs [who sometimes had five legs or hermaphroditic characteristics], other aquatic animals, and mammals. These animals were the proverbial canaries in the coal mine.